Rechargeable batteries are used in portable devices like mobile phones and notebooks. Especially, rechargeable lithium batteries having performance not degraded by memory effects are wildly used in portable devices. Safety factors are crucial when charging lithium batteries, as fires or explosions might occur if under abnormal conditions or incorrect operations. Therefore, commercialized lithium battery sets must provide protection circuits for controlling charging/discharging operations. Multi-functional fuses (protection components) have the advantage of taking up smaller space and providing multiple protections, thus being often used as a basic part of lithium battery sets nowadays. Many corporations and research institutes have spent resources on developing a plurality of multi-functional fuses for commercial benefits from rechargeable battery and other electronic equipment applications.